This test is for individuals with a clinical diagnosis of hereditary hemorrhagic telangiectasia (HHT). The primary Invitae Hereditary Hemorrhagic Telangiectasia Panel includes four genes that are definitively associated with HHT.
Individuals with clinical symptoms of HHT may benefit from diagnostic genetic testing to establish or confirm diagnosis, clarify risks, or inform management. Asymptomatic members of a family with a known HHT pathogenic variant may also benefit by avoiding specific medications (e.g., anticoagulation and anti-inflammatory agents) that can trigger symptoms.
ACVRL1 ENG GDF2 RASA1 SMAD4
ACVRL1 ENG GDF2 RASA1 SMAD4
Hereditary hemorrhagic telangiectasia (HHT) is a vascular dysplasia characterized by the presence of multiple arteriovenous malformations (AVMs), an abnormality of the development of arterial and venous vessels, which result in direct connections between arteries and veins due to the lack of intervening capillaries. Small AVMs that occur near the skin surface and are markedly visible are known as telangiectasias. Individuals with HHT are at risk for spontaneous and recurrent nosebleeds (epistaxis) and hemorrhages in the brain, liver, lungs, or other organs.
This test covers the most common genetic causes of HHT. Pathogenic variants in ENG and ACVRL1 account for 60%-80% of clinical HHT cases. The remaining genes on this panel account for an unknown proportion of HHT cases.
HHT is an autosomal dominant condition.
HHT exhibits age-related penetrance, meaning individuals who inherit a predisposition to develop HHT will have an increased manifestation of symptoms over their lifetime. Most individuals with HHT present with age-related symptoms, typically occurring at or after adolescence. Because HHT is a developmental disorder, severely affected infants have also been reported. Variable expression has been reported within families as well.
The prevalence of HHT is between 1 in 5,000 and 1 in 10,000 people.
This test may be considered for individuals with:
For links to published management guidelines, please refer to our Management guidelines page.
Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).
Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence in the transcript listed below. In addition, analysis covers the select non-coding variants specifically defined in the table below. Any variants that fall outside these regions are not analyzed. Any specific limitations in the analysis of these genes are also listed in the table below.
Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.
|Gene||Transcript reference||Sequencing analysis||Deletion/Duplication analysis|